For my 2006 RX330:

I recently decided to use my creditcard key. Upon returning from a flight (car sat 3 days), I had trouble starting the engine. The key was in the ignition and the transponder ("credit card") was positioned right near it. I've done this before without trouble. This time the car would not start. FINALLY it did.

I am wondering if there is a battery inside the "creditcard" that might be low? There is a rectangular door on the reverse that appers to be "openable". But I cannot get it opened. Maybe if I pry it but that will scratch...it doesn't seem that Lexus would design it that way. Perhaps that rectangle is a chip that doesn't get user replaced? And perhaps there is no battery but that the chip interacts with the car without it's own battery source? And maybe since I had not used the creditcard key in a few years it needed to "wake up".

Any help wold be appreciated.

 

Nope - there is no battery - behind this "door" sits just the transponder chip, like this:

Here is the card key opened:

Perhaps you should keep the card closer to the reader - After security indicator stops flashing and then turn key to "START" position.

 

Thank you for that info. I reread the instructions and I suspect I did not have the transponder close within the 10 seconds allowed. Or I turned the key too soon....before the security light went off. Now that I've reread the instructions and followed them, it works fine!

 

Had the same issue, will strictly follow the Instructions and see. There is no battery, was wondering about that too.

 

I suspect easy user error is one reason they discontinued this. Plus most Lexi (all?) are push button start now.

 

Lexus couldn't design a proper smart key, period. Too many of those before push button start just fell apart in the owner's hand.

 

I don't get that last comment. My 2009 LS460 has push button start that's always worked great. And the fob that you carry in your had doesn't have anything to do with the push button (other than sending a passive radio signal letting the car know that it's in the vicinity.)

 

Prior to the push-button start, many of the shell casings (which the blade are molded into) would just break. It is a huge problem on the RX300..

I guess the last comment meant that since you really don't use a key now anyways (and there is no keyhole), there is no need for a credit-card style key.

 

Ah! I agree. One of my RX330 keys did that. It's held together with a black electrical tie and was retired to back-up key status.

 

I had several of mine break at the point where the little screw holds everything in place. Glue helps correct this sometimes, but that's still a weak point.
I have resorted to covers to keep from stressing the weak point.
Look at The Jacketstore (online) to see one solution.
They seem to work, but of course the key is much bigger, although the colors help me distinguish between my two very similar sets of car keys.

 

These JACKETSTORE holders look great for our problem. Thanks for this tip. I'll order two now!